1. Field of the Invention
The present invention relates to a raw silicon crusher that crushes raw silicon for silicon wafers used for semiconductors.
2. Description of the Related Art
Silicon wafers used for semiconductors are produced by cutting radially single crystal silicon rods by predetermined size in thickness. The single crystal silicon rods are produced by “Czochralski process.” The Czochralski process is a method of crystal growth by dipping seed crystal, mounted on a rod, into molten raw silicon before pulling upwards and rotating the rod at a same time. The raw silicon is leftover single crystal silicon after cutting out the silicon wafers, or multicrystal silicon produced by “Siemens process” or “Monosilane process,” for example.
The raw silicon is melted by heat in a silica (quartz) crucible. For efficient melting, the raw silicon is required to be crushed and reduced its size for filling easily into the crucible.
Usually, the raw silicon was crushed by humans using tungsten hammers or the like. Because crushing the raw silicon by humans is a hard work, the arts for cutting down on labor as much as possible are suggested. For example, a crusher (a jaw crusher) having tungsten carbide jaw faces, or a silicon heating and quenching machine cracking the raw silicon by quenching after heating, as described in the Patent Document 1: International publication No. 09/019,749.